Enhancement of lateral resolution of Fourier domain optical coherence tomography over diffraction-limit by defocus-detection and numerical compensation

摘要

A method of lateral superresolution for Fourier domain optical coherence tomography is presented. This method consists of intentional defocus and its numerical compensation using a spatial frequency- phase filter. The designing process of the phase filter is described, and the superresolution effect is discussed theoretically. Experimental results of a knife-edge test prove that the frequency filter enhances the lateral resolution better than a diffraction-limited resolution. This method is applied to the investigation of an in vivo human iris and shows the effect of the cancellation of defocus.